At present, a steel wire rope brake used in an elevator is mainly used as an elevator safety device of up-direction over speeding. It is adopted a mode of power-on triggering action at failure and manual mechanical resetting. There are objections between its control principle and the current standard requirements, meanwhile it is unable to meet relevant requirements for car accidental movement protection device in term of triggering control mode. Besides, in terms of resetting mode, implementation of resetting by means of manual operation is unable to meet a user's normal use requirements. In addition, the friction brake lining is small in friction coefficient, quick-wearing and short in life, and thus is also unable to meet the requirements for brake life in car accidental movement. For this purpose, an improved design is required for the existing steel wire rope brake to make it more in line with standards, perfect in function, optimized in performance and more stable in control.
By means of information retrieval of the prior art, it is found that the existing steel wire rope brake is designed based on the upgoing overspeed protection, dominated by a mechanical manual resetting mode. It is extremely inconvenient for resetting for limited operation space, higher storey and brake of an elevator without machine room. In addition, during a power-on triggering, intermediate control mechanisms are increased, control delay is long, larger electric current is required for the electromagnet, and a back-up power supply is large in capacity and high in power consumption. Therefore, the control principle, braking force and brake lining life are not suitable for car accidental movement protection. An improved design is required for the resetting mode, the triggering mode, the braking force, the control principle and so on so as to meanwhile meet the upgoing overspeed protection function and car accidental movement protection function.